The invention is directed to an attachment member for securing insulation panels to structural components. The attachment member includes an axially extending tubular shaft with a large area head on one end of the shaft. The head and shaft define an axially extending passageway containing an abutment for a fastening element used to secure the attachment to the structural component. The passageway has flexible sector-shaped parts located in the region of a recess in the head aligned with the passageway. The sector-shaped parts project radially inwardly toward and are arranged perpendicularly to the passageway axis.
A two-part attachment unit for securing roof insulation is disclosed in U.S. Pat. No. 4,884,932. The attachment unit includes a member with a head at one end of a shaft and the head and shaft form a passageway for receiving and holding a fastening element.
To avoid forming a passageway transmitting low temperature in the attachment member, a thermally insulating plug is pressed into the passageway through an aperture in the head. The attachment member has parts in the entrance into the passageway and these parts bend when the plug is introduced and are bent back by a stop shoulder of the plug, so that the plug cannot fall out of the passageway. The parts are formed of the same material as the attachment member.
This two-part attachment unit is used for securing insulation panels to a plywood lining or to wood or metal carriers arranged adjacent to one another. Nails are employed as the fastening elements. The attachment of insulation panels to metal supports by means of screws requires a long preparation period for the fabrication of appropriately threaded holes.
If such attachment units are covered by a coat of plaster, in the region of the entrance or aperture through the head there is no adequate adherence of the plaster. Because of the inserted plug, the plaster cannot reach behind the flexible parts and assure a back-gripping attachment. If the plug is not present in the aperture, it is not assured that the flexible parts are sufficiently returned in to their perpendicular position with respect to the passageway axis, since overstretching by the setting tool cannot be excluded. As a result, the flexible parts are not available for adherence of the plaster. Furthermore, if the plugs are not present, an amount of plaster will enter into the passageway affording a duct for the conduction of heat or cold.